Using paradata to estimate the average time it would take respondents to complete a computer assisted telephone interview questionnaire

Until now, years of experience in questionnaire design were required to estimate how long it would take a respondent, on the average, to complete a CATI questionnaire for a new survey. This presentation focuses on a new method which produces interview time estimates for questionnaires at the development stage. The method uses Blaise Audit Trail data and previous surveys. It was developed, tested and verified for accuracy on some large scale surveys.

First, audit trail data was used to determine the average time previous respondents have taken to answer specific types of questions. These would include questions that require a yes/no answer, scaled questions, "mark all that apply" questions, etc. Second, for any given questionnaire, the paths taken by population sub-groups were mapped to identify the series of questions answered by different types of respondents, and timed to determine what the longest possible interview time would be. Finally, the overall expected time it takes to complete the questionnaire is calculated using estimated proportions of the population expected to answer each question.

So far, we used paradata to accurately estimate average respondent interview completion times. We note that the method that we developed could also be used to estimate specific respondent interview completion times.